28 Legions

I've been gnawing on an idea for the last couple of weeks and I haven't really reached a conclusion. But nevertheless I'm struck anew by the idea every time I wrassle with it.

It is this:

We'll remember that Augustus Caesar became the first emperor of Rome (though he preferred the term princeps, or "first citizen") by defeating, among others, Marc Antony in a civil war. The army he inherited afterwards consisted of upwards of fifty legions of varying size and organization. He regularized the army at 28 legions all organized in the same way. Each legion contained 5,120 men, so the Roman army as a whole had 143,360 men. This means that during the Pax Romana, the "Roman Peace", the Romans controlled Europe, the Balkans, Turkey, chunks of Mesopotamia, the Middle East, Egypt, North Africa, and Spain, with a combined population of about 53 million people, with less than 150,000 regular soldiers.

This boggles me to a certain extent. How could the Romans control basically The West with 150,000 men under arms, while we can't seem to control Iraq with roughly the same number of men under arms? Rome had no spy satellites, no reconnaissance drones, no helicopters, no night vision equipment, no CIA, no FBI, no secret police, nothing. So how did they do it??

I think - but I can't prove - that the Romans did it, at least in part, by making people want to be in with the Roman empire. The Romans offered powerful incentives to join with them - citizenship, protection, aqueducts, baths, roads, trade, peace, orderly public administration, and a sense of being a stakeholder in the empire. The Roman empire didn't stay together because of the power of the Roman army, but because there were powerful inducements to join the empire, or least abide it in silence. The Romans were capable of extreme ruthlessness when pressed, but they were also pratical, realistic pragmatists who saw that there was a certain value in achieving their ends without bloodshed if possible.

What does this mean? I don't know yet. But I'm struck every time by the observation that the Romans maintained the peace throughout the western world with the same number of troops that we have in Iraq. There's a lesson in there somewhere, but I don't know what it is yet.

(Subsequent events proved that the Roman army of 28 legions was too small to carry out sustained field operations, and the lack of a central reserve meant that Rome was vulnerable to things like the "Varus Disaster", where three of the 28 legions were wiped out to the last man by German tribesmen. But even though later emperors raised additional legions, the count never exceeded 31 until the time of Domitian when the nature of the legion was drastically altered.)

(I also concede the point that for every Roman regular soldier, there was an auxiliary. The legions consisted almost exclusively of heavy infantry, which the Romans believed was the arm of decision. All the other types of soldiery that an army needs - archers, cavalrymen, scouts, light infantry - were supplied by the provinces in the form of auxiliaries. So it's reasonable to say that the Roman army consisted of 143,000 professional soldiers and an equal number of somewhat irregular auxiliaries, but the auxiliaries were never the heart of the army and were never (or at least almost never) used independently.)